Hydraulic pipe testing apparatus



J. c. EwAR-r HYDRAULIC PIPE TESTING' APPARATUS Feb. 5, 1957 2 Sheets-Shea?I l Filed June l, 1954 JOHN c.

llhl L Awww# I l Attorneys Feb- 5, 1957 J. c. EWART HYDRAULIC PIPE TESTING APPARATUS 2 Sheets-Sheet 2 Filed June 1, 1954 III/l,

IN V EN TOR.

JOHN C. EWAHIT @my Atorneys This invention relates to a pipe testing `apparatus and more particularly to a hydraulic apparatus for testing long lengths of substantially large diameter pipe.

In the past, large diameter pipe has been tested for structural defects by capping the ends and applying fiuid pressure within the pipe. This method requires large quantities of iiuid to fill the pipe and the lling and draining operations take a considerable period of time. In addition, the pressure exerted by the iiuid against the end caps of the pipe is of considerable magnitude, and an external force is thereby usually applied to the caps to counteract the longitudinal force of the fluid within the pipe acting against the caps. This external counteracting force, if improperly controlled, may cause a buckling of the pipe which destroys the dimensions of the pipe and its usefulness. p

With the use of the above method of testing it was not practical to test long lengths of pipe because of the quan tities or" w-ater involved and the excessive longitudinal pressures exerted by the fluid within the pipe.

The present invention is directed to a hydraulic pipe testing apparatus which is of inexpensive design and is capable of testing long lengths of substantially large diameter pipe with a minimum use of fluid.

More specifically, the testing apparatus consists of a seals outwardly against the pipe to provide a sealed, fluid-,i

tight chamber. After testing, thepipe is moved forwardly on the core to dispose a second portion of the pipe be`- tween ,the seals. This second portion of the pipe is tested in a manner similar to that of the first portion. After the second portion of the pipe has been tested, the pipe is withdrawn from the core, reversed, and the opposite Aend portion of the pipe disposedY around the core. The untested portion of the core is then tested in increments similar to that employed with the portion of the pipe rst tested. Y t

The invention incorporates a seal depresser to depress a seal at the rear end of the core to permitthe leading end of the pipe to pass over the seal. The seal depresser is 2,780,093 Patented Feb. 5, i957 foundation may be employed because of the low weight of the machine. As the high pressure fluid is confined to the annular chamber between the core and the pipe, only a small amount of fluid is required and the iiuid can be introduced and withdrawn from the chamber in an extremely short period of time.

As the testing uid is confined to the annular chamber and thereby occupies only a small proportion of the cross sectional area of the pipe, the longitudinal force of the iuid is minimized and the needfor a counteracting force on the end caps is eliminated. By eliminating the counteracting force the problem of pipe buckling is overcome.

The present apparatus permits long lengths of pipe to be tested on a relatively small apparatus, for the pipe is ordinarily tested in four increments andthus the machine need only be slightly more than one-quarter toene-third of the length of the pipe to be tested.

The drawings furnished herewith illustrate the best mode of carrying out the invention as presently contemplated and set forth hereinafter.

In the drawings:

Fig. 1 is a side elevation of the apparatus with the pipe to be tested supported on rollers prior to being disposed on the core;

Fig. 2 is a plan view of the apparatus as shown in Fig. 1;

Fig. 3 is a side elevation showing the first increment of the pipe in position on the core;

Fig. 4 is a side elevation showing the second increment of the pipe in position on the core;

Fig. 5 is an end elevation of the apparatus as viewed from the left in Figure 1;

Fig. 6 is a sectional view taken along line 6`6 of Fig` ure l;

Fig. 7 is an enlarged sectional View of the supporting ing the seal at the rearward end of the core; and

Fig. l1 is a View similar to Fig. 10 showing the seal depresser displaced rearwardly by the pipe.

slidably mounted with respect to the core, and the leading end of the pipe engages the seal depresser and moves it rearwardly out of engagement with` the seal. The seal depresser is adapted to move rearwardly a `distance equiv alent to approximately one-half the length ofthe pipe so that at least one-half of the pipe may be disposed around the core and tested.

The seal depresser is biased forwardly so that it will automatically return to engage the seal at the rear end of the core when the pipe is withdrawn from the core.

The present pipe testing apparatus is of an inexpensive design as no yokes or tie rods are reduired, and a simple As shown in the drawings, the `pipe testing apparatus of the present invention comprises a frame 1 which issupported `on a foundation 2. The frame includes a gen- Y erally vertical shaft supportplate 3 which isireinforced by websf. One end of ashaft 5 is secured to support plate 3 and thev shaft extends outwardly therefrom in a generally horizontal plane. The opposite 0r forward end of the shaft 5 supports a generally cylindrical core 6.

The core 6 consists of a shell 7 which-is reinforced at spaced intervals throughout its length by circular webs 8.

The ends of shell 7 are enclosed by end caps 9 which are welded to the shell. The forward end of `shaft 5 is se-A cured by welding to the rear end cap 9.

`A pipe'lil to be tested is adapted to be fed onto the core 6; The outer diameter of core 6 is slightly less thanV the internal diameter of pipe l@ so that the core 6 will be spaced inwar ly of the pipe toprovide an annular chami her l1 between the pipe lt) and core 6. jFluid pressure is introduced within chamber ll to test the portions of the pipe disposed aroundcore 6 for structural defects.

The pipe lil is guided onto core 6 and centeredtherearound by a pair of guide rings l2 which are disposedv at each end of the core and bear against the respective end less than the internal diameter of pipe lil. The guide portions of rings l2 serve ,to center the pipe on core 6 arid provide chamber 11 with` a uniform radial dimension so that the duid pressureV withinchamberl 11- actsequ'ally against all portions of the pipe.

The pipe is also guided in movement on core 6 by a series of guides 13 whichfare secured at spaced inter# vals tothe outer surface ofshell 7. 1 Guides 13`arealso provided with beveled approach edges andserv'e to centery the pipe around the core.

Chamber 11 is sealed at the ends of'the'core by annular resilient seals 14 which are disposed aroundthe guide rings12. The'sealsli are provided with lips 15 which extend angularly outwardly from the fbo'dyof the sealy towarda transverse planepassing.throughthe1longitu-l is slightly greaterlthan the internal diameter of vpipe-*10 sothat1the lipwillbe'biased inwardly byfthe-pipewlren theV pipe-is disposedv circumfer'en-tially tol the core.

Each; ofthe-seals` 14 issecuredlagainstf longitudinal movement by a packinglring16'and" anouter retaining v ring-17;` TheV packingyring-.161hasa generally channel-- shaped cross section and'detines Vajchamber 18 Ibetween the packing ringrandthe base/of -the'seal 14; -Aser ies"of openingsfforrned-in the web 'portion ofy thepacking ring y provide communication betweenlcham'b'er 11 and chamber 18.

FluidM pressure introduced within-chamber 11 acts againstth'e lipL-15 of the'se'al to forcethelip youtwardly into a tight sealing engagement with the pipe. In addition, ythe iuid pressure acts withintchamb'enl @against the'ubaseof'the seal 14 to insure= a tightlsealin'g engage ring 17 is bolted to the respective guide ring 12 by bolts As the lips ,-15 ofthe seals 14 project outwardly beyond the core, the lip of the rear seal is depressed in" order to permit the pipe' to 4pass over the seal. T he` rear seal 14 is adapted to be-'depressed by :a 'depresserunit whichA includesY a circular plate 21 which is slidably mounted on Vshaft 5.' Anannular flange 22-is provided on the periphery of plate`21 and ilange 22 extends forwardly of the plate-around the retaining ring 17.V The flange 2r2gisvadapted to'circumferentiallyengage the rearV seal 14ai1 ddepress the lip` ofA the'seal so Ythat the pipe 10.tobe testedcan pass over thefseal. The forward edge-` 23ofjflange 22 is provided .with la blunt contour and is adapted to be, engagedby the leading edge of the pipeV 1t) as thpipeis fed onto the core.

rlhe seal depresser unit is slidably mounted 'on shaft 5I by meanszof a bearing block 24 which -is connected to plate 21-and is slidably keyed at 25 to shaft 5, see-Fig. 6;

Asfthe Adepresser unitis slidably mounted on shaft 5, the` depresser'unitgwill be pushed rearwardly by the engagementof the 'leading end of the pipe 1@ with the ange 22.

The depresser unit is biased forwardlyl on shaft 5 so that the flange 22 will return to engagement with rear seal when theipipejtt is withdrawnl from the core 6. To .bias the depresser unitforwardly, bearing block 24 is connected. to piston rod 26 of an air cylinder 27. The depresser-unit is lmoved rearwardly bythe pipe 10 against the` pressure `in cylinder 27. lWhen the pipe 10 is with# drawn from the core, the pressurewithin cylinder 27 will move kthedepresser unit forwardly Vto 'effect engagement of flange 22 Awith the rear seal 14. l

To supply and withdraw-fluid 'pressure from chamber 11,.\ a -pair of'conduits l28,I which communicate witha source of iluid pressure, not showm are attachedto the' of the passages` `29 in turn communicates withla radial l passage 30 which extends outwardly to chamber 11. Fluid pressure is introduced through one ofthe conduits 28fand passes through the corresponding passages 29 and 30 to chamber 11. The pressure within chamber 11 acts outwardly against the pipe to test the same for structural defects. On completion of this testing operation the fluid within chamber 11 is withdrawn through the other of the passages 29 and 30 and conduit 28.

To permit the -depresser unit to slide rearwardly on shaft 5, the conduits 28 pass throughv suitable openingsA in the plate 21 and extend-generally co-extensively Vwith shaft 5 to frame 1. By this construction the seal-.zdepresser unit can move relative to the conduits 28.

It is contemplated that thepipe be tested inincrements of one-quarter to one-,third of its length. By this method of an end portion of the pipe is disposed around the core and this one-quarter to one-third length is tested. After testing, the pipe is moved rearwardly pushingthe seal depresser unit ahead of it until a second length' of pipe is disposedV about thecorel in position to betested.` An

amount of overlap is contemplated vso that all portions of Athe pipe will be tested'.

After testing of this second length,- the pipe is removed Vfrom the core, "rever-sed, and the opposite end ofthepipe is introducedI onto the` core. The untested second portion of the pipe is-then tested in two increments in a manner similar tofthatof the first one-half of thevpipe-1 To yguide and centerthe pipe' 10 one-ore 6 a roller 31 is journaled within brackets 32 which extend `outwardly and-downwardly from the forward endcap Theroller 31 is adapted to ride on the internal surface of the pipe and aids in centering the .pipe on the core.

The pipe 1l) is supported by and conveyedonto the `meshiwithgears d'securedto theroller shafts 34." Bythisiconnection, `rotation of longitudinal shaft-3S by motorr 36ieffe`cts a simultaneous rotation of rollers 33 tov move the pipe in relation to the core 6.-

Whenthe: pipe 10 is not in circumferential relationto the core', the: forward end of core 6 is supported by a support roller k41 which is rotatably secured between vthe upper endsof-spaced armsiriz.A The lower end of arms 42vare piv-otally secured to shaft 43 which is supported between thegupstanding-spaced supports 44.

The arms ,42'are providediwith outwardlyY extending ears '145; and the piston Vrod 46 of an air cylinder 471is pivotal'lylsecured.between .the i ears 45, Cylinder-'47 vis pivotallymountedbetween brackets' 43 which are secured to foundationzZl Whenrlthe piston r-od46'is in the extendedposition,` the `arms 42 Iare substantially vertical and thefsurface :of the roller' is disposed slightly above the surface of con-Y veyor rollers 33 and in position to support core 6.

As :the'pipeis moved onto the core 6, theleading end of the'pipepasse's .between I.the core and the-conveyor-.roller 33 rdisposedbeneathithe forwardend of the core.-V When 43-'andmoving roller t1-out of contact'with core 6.

above'theiroller disposed 'beneath the forwardv end# of the'-cor'e`, thereby actuating ,air cylinder i7 and moving the piston rod 46outwardlyto pivot arms42 Vandroller 41 f fupwar'dly int-0j engagement withv core 6.

n operation of the present apparatus the pipe to be tested is initially placed on the series of conveyor rollers 33 by a chain hoist or the like. The motor 36 is then operated to feed the pipe onto the core 6.

As the leading end of the pipe passes above the roller 33 disposed beneath the forward end of the pipe, the

solenoid is energized to actuate cylinder 47 and pivot support roller 41 downwardly out of contact with the core. The pipe and the core are then supported by the rollers 33.

The pipe 10 moves rearwardly with the leading end thereof engaging the surface 23 of the flange 22 of the seal depresser unit. When the flange 22 has been moved rearwardly out of engagement with the rearseal 14 by pipe 1t), the motor is stopped.

Fluid pressure is then introduced into chamber 11 through conduits 28 and passages 29 and 30 to test the portion of the pipe located between the seals 14. After this portion of the pipe has been tested and the fluid pressure `withdrawn from chamber il, the pipe is again moved rearwardly through operation of motor 36 until a second increment is positioned between the seals 14. The motor is again stopped and this portion of the pipe is subjected to the high duid pressure test. In this position of pipe l0, theseal depresser unit has been pushed rearwardly by the leading end of the pipe and is disposed adjacent the supporting plate 3 of frame l.

A'fter the second increment of the pipe has been tested, the pipe is withdrawn from the core by operation of motor 36 and the seal -depresser unit follows up the movement ofthe pipe due to the pressure exerted by air cylinder 27. As the leading end of the pipe passes above the conveyor roller 33 disposed beneath the forward end of the core 6, theelectromagnetic circuit is dez-energized to actuate cylinder 47 and pivot arms 42 and roller 41 upwardly. The support roller 41 then supports the core 6.

The pipe is then reversed on the conveyor rollers 33 and the opposite untested end of the pipe is then fed onto the core 6. The second untested portion of the pipe is then tested in a manner similar to that of the iirst half.

As the `present `apparatus is adapted to tes't long lengths of pipein small increments, die testing apparatus can be of a smaller inexpensive design than the conventional types of pipe testers. The decreased size of the apparatus results in lower weight and eliminates the necessity for costly supports and foundations.

As the fluid pressure is conned to the chamber )il rather than being introduced within the entire interior of the pipe, only a small amount of lluid is required for testing and4 the fluid can be introduced and withdrawn from the chamber in a short period oftime. This time saving speeds up the entire production of pipe.

In the conventional testing apparatus wherein the fluid is disposed within the entire interior of the pipe, substantial longitudinal forces are exerted against the end caps. However, in the present apparatus, as theiluid is contained only within the annular chamber 1l and thereby occupies only a small porti-on of the cross sectional area of the pipe, the longitudinal force of the fluid is minimized and the need for an outer counteracting force on the end caps is eliminated.

The present invention also provides a novel method of sealing the ends of ti e pressure chamber 1l. The sealing is accomplished through the use of a pair of pressure seals wherebythe sealing engagement is increased in proportion to the magnitude of pressure in the chamber.`

Theseal depresser unit serves to permit the pipe `to pass v over4 .both of theseals without injuring or damaging the subject matter regarded as 'the invention.

I claim:

1. An apparatus for testing tubular members, comprising a frame, a cylindrical core extending outwardly from the frame and adapted to circumferentially receive a tubular member to be tested, said member being spaced outwardly from the core to provide an annular chamber between the core and the member, an annular resilient sealing member disposed at each end of the core and adapted to bear against the pipe for sealing the ends of the chamber against internal fluid pressure, an annular seal protector disposed at the rearward end of the core adjacent the frame to depress the sealing member at said rearward end until the tubular member is circumferentially disposed with respect to the rearward `sealing member, said seal protector being disposed radially outward of the sealing member in position to be engaged by the end of the tubular member and moved rearwardly out of engagement with the sealing member, means for` moving the tubular member onto the forward end of said core prior `to testing and for withdrawing the member from said core after the testing has been completed, and means for introducing a high pressure into said chamber to test the portion of the tubular member disposed between the sealing members for structural defects.

2. An apparatus for testing pipe, comprising a frame, a generally cylindrical core extending forwardly from the frame and adapted to circumferentially receive the pipe to be tested and having a diameter slightly less than the internal diameter of the pipe to provide an annular chamber therebetween, an annular resilient seal disposed circumferentially of the core at each end thereof, each of said seals extending angularly outwardly from the core in a direction toward a transverse plane passing through the longitudinal center of the core and being adapted to engage the pipe to seal the chamber against internal pressure, an annular seal protector disposed in circumferentiial engagement with the seal at the rearward end of said core to depress the seal radially inwardly and decrease the diameter of said seal to an amount less than the internal diameter of the pipe to be subsequently received on said core, means for feeding said pipe onto the forward end of` said coreand moving the pipe rearwardly on said core with the leading end of the pipe engaging said seal protector, means for slidably mounting said seal protector with respect to said core to permit said protector to be moved rearwardly out of engagement with the seal by the leading end of said pipe and effect lan engagement of the seal with the pipe, means for introducing a high pressure fluid into said chamber to test the portion of the pipe disposed between the seals for defects and for withdrawing the pressure from the chamber on completion of the testing, and means for returning saidrseal protector into engagement with the seal at the rearward end of the core on withdrawal of the pipe from said core.

3. An apparatus for testing pipe, comprising a frame,

a generally cylindrical core extending outwardly from the frame in a generally horizontal plane and adapted t0 circumferentially receive a pipe to -be tested with the internal diameter of said pipe being slightly greater than the external diameter of the core to provide an annular chamber therebetween, a resilient seal disposed around the outer surface of the core adjacent each end thereof, an annular movable seal protector disposed `circumferentially of the rear end portion of the core adjacent the frame ,and adapted to circumferentially engage and depress the seal adjacent said rear end portion,` drive means for feeding the pipe to be tested longitudinally onto the forward end of said core with the leading end of said pipe engaging said seal protector and moving the same out of engagement with the seal, theends of said chamber then being closed offl by the engagement of said seals with the inner surface of said pipe, means for introducing a` high pressure `iiuid into said chamber to test the portion` ofthe pipe disposed between said seals and for with-i y `drawing said pressure from said chamber after complei tion of the testing, means for withdrawing the pipefrom the core oncompletion 4of; testing, and meansnfor biasing saidffseal protector `forwardly awayrfrorn saidlframeto .a

returnsaid yseal .protector into circumferential engage-l.

mentgwith the. sealat therrearward end of Vsaid corre after withdrawal of Vthe tubular member from the core., u

4. VAn apparatus for testing pipe comprisingnla frame,

a generally cylindrical core extending outwardlytrorn the frame and adapted to circumferentially receive the pipe to be testedand having a diameter slightly lessthan` theinternal diameter ofthe pipe, toV provide an annular chamber therebetween, an annularv resilientseal disposed cirumferentiallyof thercore at each endthereof and. l

adapted tobear. against the pipevto seal saidchamber againstiternaluid pressure,` means fordntroducing a high pressure uid into said chamber. to Vtest the portion ofthe pipe` disposed between the4 seals and to withdraw the iiuidafter completion of testing,v .conveyingmeans alignedwith'said core` with a portion of said conveyingl means., being disposed beneath said core, said conveying means serving,l to support and convey the pipe onto the core forte'stingand withdraw the pipe from the core on completion of testing, a supportingmember for supportingpthe` core prior to the introduction of the pipe onto said' core, andmeans connected to the, supporting member for withdrawing the supporting member as the leadingendtof the pipe is fed onto the core withthe core then being supported by the conveying means and for returning the supporting member into engagement withl ber therebetween, an annular resilient pressure seal dis- L' posedrat4 each end ofthe core to bear against the tubular member and seal ofi the chamber against internal lluid pressurepsaid seal being adapted toy be forced outwardlyv intola tight sealing engagement with the pipe by thel uid pressure within the chamber, an annular seal protector .slidably mounted on said shaft and biased forwardlyfaway from said fra-me to engage and depress the seal atthe rearward end of the core to permit the tubular memberlto be received therearound, drive means kfor moving said tubular member onto the forwardend of saidcoeand for stopping movement of said tubular meinberafter the leading edge 4of said tubular Vmember engagessaid seal protector and moves said seal protector rearwardly out of vengagement with the corresponding sealk with said ytubular member then beingl disposed cirn cumterentially'of said seal, Aand means for introducing high' pressure fluid into said chamber to test the portion of the tubularfmernberV disposed between said seals for structural defects and for withdrawing the pressure on completion .of testing, said drive means serving to move the tubular member rearwardly toward said frame against the biasing Vforceon said seal protector aftertesting of the frame and adapted to circurnferentially receive the y pipeto be tested and having a diameter slightly less than theinternal diameter of the pipe to provide an annular chamber therebetweem an annular' resilient seal disposed,circumferentially of the core at each end theretest the portionof thefpipe disposedbetweenlthe. seals andltowithdraw the iluidl after completion. of testing,. 4 conveyingmeans aligned with saidicore with, a portion,

of said conveyingrneans disposed beneath said core, said' conveying meansserving toV support and convey the pipe onto-'the core `for testing,` a supportingmember disposed` at theforward end of the core for supportinggthe core I prior to feeding the lpipe onto said core, and means connected to.theysupportingmember for withdrawing the `supporting member `:from the core when the leading end of the pipe passes a predetermined position between. thev forward end of the coreand said supporting member withgthe core-then being supported by the conveyingv means.

7. An apparatus vfor testing pipe, comprising a frame,

a generally cylindrical 4core extending outwardly fromthe frameA and adapted to circumferentially receive the pipe to be tested and havinga diameter slightly4 less than the; internal diameter of the pipe yto provide an annular chamber therebetween, an annular resilient seal disposed..

circumferentially of the core at each end .thereof ,and adapted tobearj againstV the pipe to seal said .chamber againstinternal uid pressure, means for introducingfa high pressure lluid into said chamber to testthe portion of the pipe-disposed between the seals and to withdrawv the fluid after completion of testing, a series of conveyor rollers` `aligned with said core for supporting said pipe with a,roller of said series disposed beneath the..

forwardend ofthe core, a supporting .member disposed beneath Athe Acore rearwardly of said roller for supporting the core,:meansfor moving said pipe on said series of rollers to feed theA pipe `onto the forward end of said` core ,for testing and yfor withdrawing the pipe` from` the core on completionof testing, and means connected to the supporting .member for withdrawing the supportlingmember when theleading end of the pipe passes between the .core and said roller with the core then being supported by said roller and for returning the supporting member .into engagement with the core when the leadingend 'of the pipepasses between the core and saidroller on withdrawal of the pipe from the core.

8. An apparatus for testing tubular members, comprising a frame, a shaft extending outwardly from the.

frame in a generally horizontal plane, a generally cylindrical core secured to theouter end ofthe shaft and disposed in axial alignment therewith, saidcore being adapted to circumferentially receive an end portion of said tubular member withsaid tubular member beingspaced outwardly from said core to provide -an annular chamber therebetween, an annular resilient seal disposed circumferentially of the core at each end thereof, each of said seals extending angularly outward from the core in a direction toward .a transverse plane passing through the longitudinal center of the core and adapted to engage the pipe tol seal the chamber against internal pressure! an annular seal protector slidably mounted on said shaft and disposed in circumferential engagement with the seal of and, being adaptedyto bear `against the pipe, to sealV saidgchamberagainst Yinternal fluid `pressure,; means for introducing a high pressure iludinto `said.chamber-to at the rearward end of said core to depress the seal radially inwardly and decrease the outer diameter. of the seal to an amount less than the internal diameter of thev pipe to be subsequently received on the core, means for feeding said pipe onto the forward end of said core and moving the pipe rearwardly on said core with the leading i end of the pipe engaging said seal protector and moving the same rearwardly out of engagement with the seal with v withdrawing the pressure from the chamber on completion' of the testing, said conduit means extending freely through the pipe'disposed between the seals for defects and fork said seal protector to permit said seal protectorv to be movedrelatively'to said conduit means.

9.V An apparatusfortestingepipe icomprising'la frame,

a generally cylindrical core extending forwardly of the frame and adapted to circumferentially receive the pipe to be tested and having a diameter slightly less than the internal diameter of the pipe to provide an annular chamber therebetween, a guide member secured to each end of the Core and having an enlarged guiding portion formed with a diameter greater than said core and smaller than the internal diameter of said pipe to aid in centering the pipe on the core and provide the chamber with a substantially uniform radial dimension, an annular resilient seal disposed circumferentially of each of the guide members adjacent said guiding portion and having a base portion disposed in engagement with said guide member and an outer lip extending angularly outward from the base in a direction toward a transverse plane passing through the longitudinal center of the core and being adapted to bear against the pipe to seal the chamber against internal pressure, a seal protector disposed adjacent the rearward end of the core and having an annular peripheral ange extending forwardly therefrom to circumferentially engage the lip of the seal at the rearward end of the core and decrease the outer diameter of said seal to an amount less than the internal diameter of the pipe to be subsequently received on said core, means for feeding said pipe onto the forward end of said core and moving the pipe rearwardly on said core with the leading end of the pipe engaging said. seal protector and moving said seal protector rearwardly out of engagement with the lip of said seal, means for introducing a high pressure uid into said chamber to test the portion of said pipe disposed between said seals for structural defects and for withdrawing said fluid pressure on completion of testing, means for withdrawing the pipe from the forward end of the core on completion of testing, and means for biasing the seal protector forwardly with respect to the core to return said Flange into circumferential engagement with the lip of the seal at the rear end of the core on withdrawal of the pipe from the core.

References Cited in the tile of this patent UNITED STATES PAT'ENTS 2,479,847 Longley Aug. 23, 1949 2,481,013 Henderson Sept. 6, 1949 2,493,061 Devine et al Ian. 3, 1950 2,610,691 Berry cpt. 16, 1952 2,652,717 Bush et al. Sept. 22, 1953 FOREIGN PATENTS 598,16() Germany June 6, 1934 635,735 Great Britain Apr. 12, 1950 

